Electric furnace.



l. HECHENBLEIKNER.

ELECTRIC FURNACE.

APPLICATION FILED NOV. 2. 1914.

1,173,960, Patented Feb. 29, 1916.

5 SHEETS-SHEET I 41 I' I I? o o v J0 G 4.9

. Jzimw flrrrs l. HECHENBLEIKNER.

ELECTRIC FURNACE.

APPLICATION FILED NOV- 2, 1914.

Patented Feb. 29, 1916.

5 SHEETSSHEET 3.

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l. HECHENBLEIKNER.

ELECTRIC FURNACE.

APPLICATION FILED NOV. 2, 1914.

Patentedv Feb. 29, 1916.

5 SHEETS-SHEET 4.

I. HECHENBLEIKNER.

ELECTRIC FURNACE.

APPLICATION FILED NOV. 2. 1914.

1, 173,960. Patented Feb. 29, 1916.

5 SHEETSSHEET 5- a VBLEIHIVIIT. E y W fi M UNITED STATES PATENT" OFFICE.

INGEN UIN HECHENBLEIKNER, OF CHARLOTTE, NORTH CAROLINA, ASSIGNOR TO SOUTHERN ELECTRO CHEMICAL COMPANY, OF

' Y won or NEW JERSEY.

NEW YORK, N. Y., A CORPORA- ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Feb. v29, 1916.

I Application filed November 2, 1914. Serial No. 889,880.

To all whom it may concern:

Be it known that I, INGENU'IN Human-- BLEIKNER, a subject of the Emperor of Aus tria, residing at Charlotte, in the State of North Carohna, United States of America, have invented certain new and useful I mprovements in Electric Furnaces, of which the following is a specification.

This invention relates to improvements in electric furnaces and especially to such as are adapted for treatment of phosphate rock to expel phosphoric acid, and the objects of the invention are to overcome the peculiar difiiculties usually found present in treatmgphosphate rock and the slag formed therefrom in the electric furnace, and it consists essentially of the improved constructmnand arrangement of parts hereinafter descrlbed in detail in the accompanying specification and drawings. I

In the drawings, Figure 1 1s a. vertical section through an embodiment of the i'nvention partially in elevation. Fig. 2 1s a side elevation. Fig. 3 is a plan view. Fig. 4 is a sectional detail through the manhole. Fig. 5 is a detail, being the side view of the electrode clamp. Fig. 6 is an end view of the electrode clamp. Fig. 7 is a sectional detail of the electrode support. Fig. 8 15 a sectional detail of the bottom tap hole on the furnace. Fig. 9 is a cross sectional detail of the upper or slag tap hole. Fig. 10 is a detail in elevation of feeding mechanism. Fig. 11 is an elevation of the feeding device.

Like characters of reference refer to like parts in all the figures.

The electric furnace itself may, in the present invention, be said to consist of three parts comprising the bottom section A, the tapered stack section B and the outlet elbow C. These parts are detachably connected and fit together, the detachable connection between the bottom portion and tapered stack section being effected by abutting channel sections 10 and 11 which are bolted or otherwise clamped together while the detachable connection between the tapered stack section and the elbow section is effected by similar channel steel sections 12 and 13 which are similarly connected together. The bottom section A is water-cooled and is, in fact, practically in the form of a water jacket, being formed with inner and outer walls 14 and 15 of thin sheet metal separated and connected together by I-beams 16 or the like and having means for circulating water in the interior and equally therethrough.

To effect an even distribution of water, an annular outlet channel 17 is formed around the top on the exterior into which equally dlstributed overflow pipes 18 are arranged to discharge, such overflow pipes extending in a radial direction from the intenor of the water jacket. The inflowing water s adapted to pass through a conduit l9 WhlCh opens at the top of the water acket.

The furnace is originally constructed without any limng in the bottom section whatever. The water jacket, however, bemg considerably cooler than the slag formed within the furnace will cause a portion of the slag to freeze to the inner wall of the water acket to thereby form a lining D of frozen slag. It is found that a lining of this distributing the same character is the only one which will resist the action of the calcium silicate slag. It is impractlcable to use any form of firebrick or other lining generally used in electric furnaces, owing to the fact that such lining will be readily attacked by the phosphoric acid and calcium silicate slag. The body portion rests on suitable transverse bearing 20 conveniently formed of wood or like insulating material. On one side of the body portion a slag overflow E is provided which is kept open during the operation and which is so arranged that the molten slag seals the furnace. This slag overflow includes a U- shaped hollow water cooled member 22 which extends upwardly in an inclined direction from the slag outlet 23 formed in the body portion and is provided with a curved water cooled mouth 24 as shown in Fig. 9, the member 22 being suitably fastened to the exterior of the water jacket. Suitable manholes 25 are also formed around the body portion having water cooled doors 26, the inner sides of the water cooled doors bleing covered with a layer 27 of frozen s ag.

The tapered section B of the furnace is not water cooled and is adapted to carry the electrodes F which extend in an inclined direction through it. The electrodes are each surrounded by a water cooled holder 30 mounted in projections 31 formed on the side of the tapered portion. Each electrode is adapted to be adjusted and regulated in position manually or automatically through the medium of water cooled electrode clamps G which are mounted on trolleys H which run on suitable tracks I.

The clamps G each comprise a pair of semi-circular hinged clamping members 32 and 33 each hinged to a bracket 34 which is secured to the trolley H. These clamps are hollow and water cooled and may be connected together at their lower extremities by a tightening bolt 36 whichextends through lugs 37 and 38 in each of the semicircular clamps.

The track I is conveniently in the form of an I-beam and the trolley H is provided on opposite sides with a plurality of trolley wheels 39, the diameter of which is such as to substantially fill the distance between the flanges of the I-beam I. The current connection for each electrode may be made by flexible current conductors 40 which are connected to the sides of the clamps G. To provide for the changing of electrodes, a plurality of stirrups 41 are provided at intervals on the track I adapted to hangin position so that they may conveniently support the electrodes which are to be inserted to be used to replace the one which has been withdrawn. The tracks I may be braced by suitable beams 42 which connect the track with the top of the tapered section. The elbow section C is adapted to discharge the furnace gases in a lateral direction and also carries a feeding means. This feeding means is adapted to distribute the material to be treated in a uniform manner and includes a hopper 45 fro-m the bottom of which two diverging conduits 46 and 47 extend which finally discharge into'opposite sides of the elbow section a short distance above its juncture with the tapered: section. A suitable sliding gate 48 may be provided to control the feeding of material. Both the tapered section and the elbow section are conveniently covered with a suitable insulating means such as a layer of asbestos 49 held in position by a suitable layer of sheet metal 50.

In ractically using the invention in the manu acture of phosphoric anhydrid from which phosphoric acid may be made, suitable quanties of natural phosphate rock, silicious material and carbon are mixed together and fed to the electric furnace. An alternating current is preferably used. The heat of the arc and the resistance heat developed within the furnace will expel phosphoric acid'and phosphorous vapor from the furnace mixture, leaving a calcium silicate slag which as it accumulates will overflow through the slag overflow E. The phosphorous and phosphoric anhydrid expelled from the furnace gases will be suitably oxidized and caught by suitable absorption means, such for example as those shown in my 'U nited States Patent Number 1,112,211, granted on September 29th, 1914. The walls of the body portion will be effectively protected from the action of the slag and phos phoric acid by the layer of molten sla which will form on it. a

It will be observed that the tapered portion of the furnace is a considerable distance above the electrodes and above the reaction zone whereby the gases liberated by the reaction will uniformly preheat that portion of the charge which is in the tapered portion and stack of the furnace. It will also be observed that as the heat of the furnace might collect to overheat either the electrodes, the feeding mixture or the wall of the furnace.

It is essential for the commercial advantages of this process in the manufacturing of phosphorous or phosphoric acid, that the temperature be well regulated and the immense heat of the electric are be so ap lied as to prevent, a local overheating o the charge or the slag. Overheating of the charge or slag will cause a distillation of not only phosphorus but will also procure the distillation of silicium and silicium compounds. Silicium and silicium compounds are mostly the cause for killing the phosphorus or in case the phosphorus is oxidized afterward for the manufacturing of phosphoric acid, said phosphoric acid is forming water insoluble, commercially worthless compounds from S10 and P 0 To prevent this disadvantage in the process the typical design of the furnace is the most important feature.

Tests have shown that in the case of this furnace the charge is moving regularly and under a steady pressure downward between and around the electrodes. In this way the once melted and reduced slag is removed quickly out of the dangerous arc zone before overheating can take place. Fresh material replacing quickl the melted slag prevents widely difierent embodiments of my invention, within the scope of the claims, constructed without departing from the spirit or scope thereof, it is intended that all matter contained in the accompanying specification and drawings should be considered as illustrative only.

What I claim as my invention is:

1. In an electric furnace, a track, a trolley mounted thereon, water cooled hinged clamping members depending from the trolley and adapted to engage an electrode.

2. In an electric furnace, a track, a trolley mounted thereon, water cooled hinged clamping members depending from the trolley and adapted to engage an electrode, and stirrup members mounted on the track adapted to support an electrode.

3. In an electric furnace, a track, a trolley mounted thereon, electrode supporting means 23 depending from the trolley, and a plurality of stirrups supported independently of the trolley and adapted to temporarily support the electrode during change of electrodes.

In witness whereof I have hereunto set my 23 hand in the presence of two witnesses.

INGENUIN HEGHENBLEIKNER.

Witnesses:

W. H. MARTIN, Jr., L. A. Ausrm. 

